Bucket actuating linkage for tractor mounted loader



June 25, 1968 H. w. BORER ETAL BUCKET: ACTUATING LINKAGE FOR TRACTOR MOUNTED LOADER Filed June 6, 1966 MUWVU INVENTORS HERBERT W Boner: ROY R BUCK Q 3.; $7M? v ATTORNEYS United States Patent 3,389,820 BUCKET ACTUATING LINKAGE FOR TRACTOR MOUNTED LOADER Herbert W. Borer and Roy R. Buck, Naperville, Ill., assigncrs to Caterpillar Tractor Co., Peoria, HL, a corporation of California Filed June 6, 1966, Ser. No. 555,525 1 Claim. (Cl. 214-776) ABSTRACT OF THE DISCLOSURE Loader bucket linkage wherein lift and tilt linkage members are disposed between closely spaced brackets and a special design of tilt linkage prevents interference with a lift jack which acts between the brackets.

For the sake of overall machine design and efiiciency, bucket support and control mechanism is preferably disposed forwardly of the operators station on the tractor upon which the bucket is mounted and desirably has a low profile to prevent interference with the operators view during a loading operation. Generally the support for the loader bucket and its actuating means is in the form of upstanding brackets or towers disposed at the sides of the tractor. In track-type tractors, there is very little space between the frame and the track so that further design limitations are imposed on the bucket support and operating means.

It is an object of this invention to provide bucket support and operating means with an improved bucket tilt linkage which enables an unusually low and narrow support tower construction and is capable of withstanding heavy loads.

The invention, together with its objects and advantages, can best be understood by the detailed description which follows having reference to the accompanying drawing.

In the drawing:

FIG. 1 is a view in side elevation of the forward portion of a tractor with a bucket mounted thereon showing the bucket in two positions; and

FIG. 2 is an enlarged fragmentary perspective view with parts in section illustrating details of a part of the linkage shown in FIG. 1.

In FIG. 1 of the drawing, a bucket is shown as pivotally connected to a pair of lift arms, one of which is shown at 11, the upper ends of which are pivoted as at 12 to towers 13. There is one tower on each side of the tractor and each tower is made up of two spaced plates, the plates not shown in FIG. 1 being shown at 14 in FIG. 2. The lift arms and bucket are raised and lowered by a pair of hydraulic jacks, one of which is shown at 16, and the rod of which is pivoted to a bracket 17 on the lift arm. The jack cylinder is mounted on trunnions disposed between the plates or walls of the towers as shown at 18.

Extension and retraction of the lift jack 16 moves the bucket from the lowermost position illustrated in FIG. 1 to the raised or carry position shown in broken lines in the same figure. The bucket can be rocked about its pivotal connection, shown at 20 with the lift arms and is shown in full lines in the position which it occupies after it has been loaded and racked back. When the lift arms are raised to the carry position, the bucket is au- 3,389,820 Patented June 25, 1968 tomatically held in the position in which it retains its contents. This is accomplished by tilt linkage connected between the lift arms and the bucket, there being two such linkages and each comprising a link 22 connected between the bucket and a lever 23 which is pivoted to the lift arm as at 24 and has a pivotal connection 25 with the rod 26 of a tilt jack 27. The tilt jack 27 is pivoted as at 28 to a second lever 29 which is pivoted to the lift arm :as at 30 and anchored at its lower end as by a pin 31 to a link 32 which is in turn pivoted on a pin 33. The construction in this area is best illustrated in FIG. 2 wherein the lever 29 is shown as formed of two spaced parts disposed on opposite sides of the lift arm 11 and also disposed on opposite sides of a pivoted anchor link 32. Extending between the pivot pin 12 of the lift arm and the pivot pin 33 of the anchor link is a stationary link 34 which forms a spacer providing room for the parts of the levers 29 on opposite sides of the lift arms and also provides large bearing surfaces for the pins 12 and 33.

The tilt linkage is of a type that is conventional in loaders and causes the bucket to be held in substantially the same position with respect to the ground during the movement of the lift arms from the lower position to the upper position shown. This makes it unnecessary for the operator to adjust the tilt linkage by energizing the jacks 27 during the lifting movement and, after the bucket has been raised and the tractor driven to the position where the load is to be discharged, the bucket is moved to a dump position by extension of the jacks 27 which causes forward pivotal movement of the bucket until pads 35 on the levers 23 engage stops 36 on the lift arms.

It has been common practice to anchor a member such as the lever 29 with two links comparable to the link 32 but spaced apart and connected to the outside of the tower 13 in order to avoid interference with the lift jacks 16. According to the present invention and for the purpose of reducing the overall width of the towers and related mechanism, as well as to provide a low profile, a single link 32 of much shorter length than previously used has been employed and so combined with the geometry of the other linkage that upon raising of the lift arms the lever 29 causes the pivotal connection 31 to swing in an are about the pivot 33 thus swinging the link 32 to the upper position illustrated in FIG. 1 while the bucket is moved to its raised position thus carrying it out of the way of the lift jack 16 which is also swinging upwardly to the broken line position in FIG. 1. As is apparent from FIG. 1, the lower position of the link 32 and lever 29 would interfere with the jack 16 in its raised position but this interference is avoided by the shortness of the link and the path that it travels during lifting of the arms 11.

We claim:

1. In loader bucket actuating linkage including a bucket pivoted at one end of a pair of lift arms, pivot means supporting each lift arm at its opposite end between two walls of a support tower on a tractor, a lift jack between said walls for raising and lowering the lift arms, and power actuated bucket tilt linkage connected between the bucket, the lift arms and the towers, the improvement which comprises a short anchor link pivoted between the tilt linkage and each support tower directly above the lift jacks arranged to swing from a generally downwardly extending position to a generally upwardly extending position while remaining entirely above the 3 4 lift jacks to avoid contact with the lift jack when the References Cited bucket is moved upwardly, said tilt linkage inclnding a UNITED STATES PATENTS two part lever pivoted to opposite sides of the hit arm and pivoted at one end to opposite sides of the short 2,986,292 5/ 1951 Kampeft 6t 214-776 anchor link, said pivot points in each tower for the lift 5 3,161,307 9 4 S hick t al- 214-776 X arms being spaced from the pivot points for the anchor 2,455,474 12/1948 Drott et al 214776 X links, and a member extending inwardly from each tower 2,817,448 12/ 1957 Pilch 214-776 wall and including a bearing for the lift arm and anchor link pivots. HUGO O. SCHULZ, Primary Examiner. 

